BEIRUT — Facing international condemnation for its bloody crackdown on protesters, the Syrian regime is expanding an intimidation campaign to keep people off the streets, according to human rights activists.

They report a sharp escalation in arbitrary arrests and unexplained disappearances — including people being plucked from their homes and offices in the middle of the day. One prominent activist in an upscale Damascus neighborhood was reportedly bundled into a car after being beaten by security officers.

“Syrian cities have witnessed in the past few days an insane escalation by authorities who are arresting anyone with the potential to stage protests and demonstrations,” Ammar Qurabi, who heads the National Organization for Human Rights in Syria, told The Associated Press on Tuesday.

“The arrests have transformed Syria into a large prison,” he said, estimating that more than 1,000 people had been detained since Saturday in raids on houses.

Syrian forces have badly treated many detainees, Amnesty International said. One was forced to lick his own blood off the floor after he was stripped and beaten, the group said.

The stepped-up campaign will have its first major test Friday — the main day for protests in the Arab world. But there were signs the protests will continue, with thousands of people gathering Tuesday in the coastal town of Banias, demanding freedom and urging the demise of Syria’s authoritarian regime, two witnesses said.

“So far it is a peaceful protest,” one person said, asking not to be identified for fear of reprisals. “Some people are carrying loaves of bread and baby’s milk because our city is under siege and we can’t come or go. ... We are running out of supplies.”

President Bashar Assad is determined to crush the six-week revolt, the gravest challenge to his family’s 40-year dynasty. Assad inherited power from his father in 2000, and has maintained close ties with Iran and Islamic militant groups such as Hezbollah in neighboring Lebanon and Hamas in Gaza.

Rights groups say at least 545 Syrians have been killed since the uprising began in the blockaded southern city of Daraa, spreading quickly across the nation of some 23 million people.

Most of the unrest erupts after Muslim prayers on Fridays, and the regime’s response has become increasingly brutal. Now, instead of waiting for the weekly protests, security forces are using the midweek lull to send an intimidating message.

An activist in Banias said the local branch of the political security department called a mechanic Sunday to fix one of its cars and he has not been heard from since. Three other men have been missing for days after security agents picked them up at a gas station, he said.